Watson ballooned to 272 pounds shortly after injuring his hamstring two days before the season opener. This was no way to start his ninth NFL season, so the 30-year-old initially scarfed down SusieCakes and barbecue, on top of the “baby weight” he gained during his wife’s pregnancy.
San Francisco 49ers’ Dekoda Watson (97) answers questions from the news media following a joint practice with the Denver Broncos during training camp at Levi’s Stadium in Santa Clara, Calif., on Wednesday, Aug. 16, 2017. (Anda Chu/Bay Area News Group)

“I tried to eat the pain away,” Watson said. “As I got closer (to returning), I knew I had to do something different with my diet.”

He’s not a full-blown vegetarian, yet. He did, after all, spend last weekend’s break amid Texas’ barbecue temptations, all while on a hunting expedition.

Known more for his special-teams prowess, the 49ers had envisioned a bigger defensive role for Watson until his injury. His subsequent weight loss helped his knees, and his speed and power are showing in the pass rush, which the 49ers lacked before he came off the short-term, injured-reserve list.

Not only did Watson feast on the Raiders’ makeshift offensive line but so did his teammates. They stacked up eight sacks, led by Cassius Marsh’s 2 1/2 sacks off the edge opposite Watson. Playing just 17 of 57 snaps at defensive end in their nickel package, Watson had 1 1/2 sacks and three quarterback hits.

“Dekoda played very well, and I thought it helped a lot,” coach Kyle Shanahan said. “Dekoda has probably got our best speed off the edge, just coming off the ball fast, and he can turn it into power very quickly.”

Watson had no sacks in his previous two seasons with the 49ers, and only four sacks in seven seasons elsewhere (Tampa Bay, Jacksonville, Dallas, New England and Denver).

Only six current teams have more sacks than the 49ers’ 24. It’s a surprising stat considering how poor their pass rush looked amid a six-game losing streak prior to Thursday’s rout of the Raiders.

After ignoring pass rushers in the draft and whiffing in free agency on Jeremiah Attaochu, the 49ers have since tried injecting talent into that pass-rushing unit. In two instances, they made unsuccessful attempts to lure two of the Raiders’ former sack artists — Khalil Mack, prior to his trade to Chicago, and Bruce Irvin, who signed Wednesday with the Atlanta Falcons.
Dallas Cowboys quarterback Cooper Rush (7) passes as he’s pressured by 49ers’ Dekoda Watson (97) in the first quarter of their NFL game at Levi’s Stadium in Santa Clara, Calif., on Thursday, Aug. 9, 2018. (Jane Tyska/Bay Area News Group)

“Having that speed on the edge that Dekoda brings, and also the bull rush he has condenses the pocket, it got him some production, but also helps other people around him,” Shanahan added.

So, with six games to go, the 49ers forge ahead with the pass rushers they banked on through training camp: Watson, Marsh, Ronald Blair and Solomon Thomas. DeForest Buckner has registered a team-high 5 1/2 sacks as primarily an interior rusher, and Arik Armstead has come on with three sacks.

Next up is the New York Giants’ Eli Manning, who’s been sacked a league-high 31 times.

Watson, reflecting on his season debut, added: “It wasn’t about sacks. We needed energy and we need to keep positive momentum.”

— Punter Bradley Pinion won NFC Special Teams Player of the Week honors. He averaged a season-best 48.0 net yards on three punts, the first of which soared a season-long 64 yards and pinned the Raiders at their 6-yard line.